CX980 vs MX980

What is the difference between these 2 headphones (Sennheiser CX980 vs MX980)? i can only find one and that is that the MX is 14$ more. please help. Also is Sennheiser a great brand for headphones? and are there any better earbuds in the 100to 200$ range? And one last thing, i found a pair of Ultimate Ears Triple Fi 10 Noise Isolating Earphone for 170$. Are those any good, because they have come down a lot in price and gotten many good reviews.